Recently in May, Stephen Hawking made a prediction that humanity has 100 years left on Earth. But, now he estimates that the only way to prolong humanity’s existence is for us to find a new home, on another planet.

While speaking at the Starmus Festival in Trondheim, Norway, he said, “If humanity is to continue for another million years, our future lies in boldly going where no one else has gone before.”

“Specifically, we should aim for another Moon landing by 2020, and work to build a lunar base in the next 30 years, projects that could help prepare us to send human beings to Mars by 2025.”

Although, Hawking is not the only one who is thinking about revisiting the Earth’s cosmic satellite. Even Donald Trump, the president of US wants to put humans on the Moon by 2020.

Additionally, various government and private space agencies are already in the works. For instance, NASA‘s mission to Mars notes that setting up an orbital lunar station would be a key step for a future mission to the Red Planet.

For private space agencies, the Moon seems to be more of a special tourist attraction than a permanent domicile. SpaceX is already preparing for its first privately funded round trip to the Moon.

But Hawking is aiming for the Moon (again), not only about survival. But strengthening humanity while we’re still on Earth for however many years we have left here.

Hawking said, “We are running out of space and the only places to go to are other worlds. It is time to explore other solar systems. Spreading out may be the only thing that saves us from ourselves. I am convinced that humans need to leave Earth for prolonging humanity’s existence.”

“I hope it would unite competitive nations in a single goal, to face the common challenge for us all. A new and ambitious space program would excite (young people), and stimulate interest in other areas, such as astrophysics and cosmology.”